Ultra-wide-band long-wavelength photodetectors

Developments and performances of ultra-wide-band long-wavelength photodetectors are outlined. Theoretical consideration shows the competence of the waveguide p-i-n photodetector for ultra-wide-band long-wavelength optical fibre communication. A newly proposed multimode waveguide p-i-n photodetector with mushroom-mesa structure can relax the parasitic limits, and reaches a record performance of 110 GHz bandwidth and 50% external quantum efficiency at a 1.55 m wavelength. A high-speed monolithically integrated photoreceiver using the waveguide p-i-n photodetector is also presented.